1 /* 2 * Copyright (c) 1995 John Birrell <jb@cimlogic.com.au>. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the author nor the names of any co-contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include "namespace.h" 34 #include <sys/mman.h> 35 #include <signal.h> 36 #include <stdlib.h> 37 #include <string.h> 38 #include <errno.h> 39 #include <pthread.h> 40 #include "un-namespace.h" 41 #include "libc_private.h" 42 43 #include "thr_private.h" 44 45 /* Used in symbol lookup of libthread_db */ 46 struct pthread_key _thread_keytable[PTHREAD_KEYS_MAX]; 47 48 __weak_reference(_pthread_key_create, pthread_key_create); 49 __weak_reference(_pthread_key_delete, pthread_key_delete); 50 __weak_reference(_pthread_getspecific, pthread_getspecific); 51 __weak_reference(_pthread_setspecific, pthread_setspecific); 52 53 54 int 55 _pthread_key_create(pthread_key_t *key, void (*destructor)(void *)) 56 { 57 struct pthread *curthread; 58 int i; 59 60 _thr_check_init(); 61 62 curthread = _get_curthread(); 63 64 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 65 for (i = 0; i < PTHREAD_KEYS_MAX; i++) { 66 67 if (_thread_keytable[i].allocated == 0) { 68 _thread_keytable[i].allocated = 1; 69 _thread_keytable[i].destructor = destructor; 70 _thread_keytable[i].seqno++; 71 72 THR_LOCK_RELEASE(curthread, &_keytable_lock); 73 *key = i + 1; 74 return (0); 75 } 76 77 } 78 THR_LOCK_RELEASE(curthread, &_keytable_lock); 79 return (EAGAIN); 80 } 81 82 int 83 _pthread_key_delete(pthread_key_t userkey) 84 { 85 struct pthread *curthread; 86 int key, ret; 87 88 key = userkey - 1; 89 if ((unsigned int)key >= PTHREAD_KEYS_MAX) 90 return (EINVAL); 91 curthread = _get_curthread(); 92 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 93 if (_thread_keytable[key].allocated) { 94 _thread_keytable[key].allocated = 0; 95 ret = 0; 96 } else { 97 ret = EINVAL; 98 } 99 THR_LOCK_RELEASE(curthread, &_keytable_lock); 100 return (ret); 101 } 102 103 void 104 _thread_cleanupspecific(void) 105 { 106 struct pthread *curthread; 107 void (*destructor)(void *); 108 const void *data; 109 int i, key; 110 111 curthread = _get_curthread(); 112 if (curthread->specific == NULL) 113 return; 114 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 115 for (i = 0; i < PTHREAD_DESTRUCTOR_ITERATIONS && 116 curthread->specific_data_count > 0; i++) { 117 for (key = 0; key < PTHREAD_KEYS_MAX && 118 curthread->specific_data_count > 0; key++) { 119 destructor = NULL; 120 121 if (_thread_keytable[key].allocated && 122 (curthread->specific[key].data != NULL)) { 123 if (curthread->specific[key].seqno == 124 _thread_keytable[key].seqno) { 125 data = curthread->specific[key].data; 126 destructor = _thread_keytable[key]. 127 destructor; 128 } 129 curthread->specific[key].data = NULL; 130 curthread->specific_data_count--; 131 } else if (curthread->specific[key].data != NULL) { 132 /* 133 * This can happen if the key is 134 * deleted via pthread_key_delete 135 * without first setting the value to 136 * NULL in all threads. POSIX says 137 * that the destructor is not invoked 138 * in this case. 139 */ 140 curthread->specific[key].data = NULL; 141 curthread->specific_data_count--; 142 } 143 144 /* 145 * If there is a destructor, call it with the 146 * key table entry unlocked. 147 */ 148 if (destructor != NULL) { 149 THR_LOCK_RELEASE(curthread, &_keytable_lock); 150 destructor(__DECONST(void *, data)); 151 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 152 } 153 } 154 } 155 THR_LOCK_RELEASE(curthread, &_keytable_lock); 156 munmap(curthread->specific, PTHREAD_KEYS_MAX * sizeof(struct 157 pthread_specific_elem)); 158 curthread->specific = NULL; 159 if (curthread->specific_data_count > 0) { 160 stderr_debug("Thread %p has exited with leftover " 161 "thread-specific data after %d destructor iterations\n", 162 curthread, PTHREAD_DESTRUCTOR_ITERATIONS); 163 } 164 } 165 166 int 167 _pthread_setspecific(pthread_key_t userkey, const void *value) 168 { 169 struct pthread *pthread; 170 void *tmp; 171 pthread_key_t key; 172 173 key = userkey - 1; 174 if ((unsigned int)key >= PTHREAD_KEYS_MAX || 175 !_thread_keytable[key].allocated) 176 return (EINVAL); 177 178 pthread = _get_curthread(); 179 if (pthread->specific == NULL) { 180 tmp = mmap(NULL, PTHREAD_KEYS_MAX * 181 sizeof(struct pthread_specific_elem), 182 PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); 183 if (tmp == MAP_FAILED) 184 return (ENOMEM); 185 pthread->specific = tmp; 186 } 187 if (pthread->specific[key].data == NULL) { 188 if (value != NULL) 189 pthread->specific_data_count++; 190 } else if (value == NULL) 191 pthread->specific_data_count--; 192 pthread->specific[key].data = value; 193 pthread->specific[key].seqno = _thread_keytable[key].seqno; 194 return (0); 195 } 196 197 void * 198 _pthread_getspecific(pthread_key_t userkey) 199 { 200 struct pthread *pthread; 201 const void *data; 202 pthread_key_t key; 203 204 /* Check if there is specific data. */ 205 key = userkey - 1; 206 if ((unsigned int)key >= PTHREAD_KEYS_MAX) 207 return (NULL); 208 209 pthread = _get_curthread(); 210 /* Check if this key has been used before. */ 211 if (_thread_keytable[key].allocated && pthread->specific != NULL && 212 pthread->specific[key].seqno == _thread_keytable[key].seqno) { 213 /* Return the value: */ 214 data = pthread->specific[key].data; 215 } else { 216 /* 217 * This key has not been used before, so return NULL 218 * instead. 219 */ 220 data = NULL; 221 } 222 return (__DECONST(void *, data)); 223 } 224 225 void 226 _thr_tsd_unload(struct dl_phdr_info *phdr_info) 227 { 228 struct pthread *curthread; 229 void (*destructor)(void *); 230 int key; 231 232 curthread = _get_curthread(); 233 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 234 for (key = 0; key < PTHREAD_KEYS_MAX; key++) { 235 if (!_thread_keytable[key].allocated) 236 continue; 237 destructor = _thread_keytable[key].destructor; 238 if (destructor == NULL) 239 continue; 240 if (__elf_phdr_match_addr(phdr_info, destructor)) 241 _thread_keytable[key].destructor = NULL; 242 } 243 THR_LOCK_RELEASE(curthread, &_keytable_lock); 244 } 245